Novel nanoparticles react to radiotherapy to kill cancer from within

Radiation therapy is currently one of the best treatments we have against cancer, but it could benefit from being more targeted to spare healthy cells. Now, researchers in Japan have developed nanoparticles that can penetrate tumors and kill them from within, after being activated by external X-rays.

Normally, radiation therapy works by damaging the DNA of the cancer cells, and part of that damage comes from the generation of reactive oxygen species. But this requires oxygen, which can be scarce at the center of tumors and limit the effectiveness of the treatment.

So for the new study, scientists at Kyoto University and colleagues investigated a different way to use radiation to kill cancer cells. They designed nanoparticles that infiltrate tumors, and once inside, they can be activated by X-rays to destroy the cells using a different method – the photoelectric effect, where a material emits electrons in response to electromagnetic radiation.

The nanoparticles are made of organosilica and carry iodine in their pores. The iodine is the active ingredient there, releasing electrons when irradiated at relatively low levels. The electrons then cause double-strand breaks in the nuclear DNA of the cancer cells, which triggers cell death.